BEIRUT: The Syrian army shelled residential areas and unleashed gunmen Wednesday, and a human rights group said at least 18 people were killed, including an 8-year-old boy. The shelling of neighborhoods evoked memories of the Assad regime's brutal, 40-year legacy of crushing dissent. Syrian activists and protesters involved in the seven-week-long uprising renewed their cries for the world to join them in calling for embattled President Bashar Al-Assad to give up power. “The Syrian people are being killed and Bashar knows that he has a free hand. Nobody is really stopping him,” a 28-year-old Syrian from the besieged seaside city of Banias said. Al-Assad is determined to crush the uprising despite international pressure and sanctions from Europe and the United States. European countries summoned Syrian ambassadors Wednesday to threaten a new round of sanctions if the regime fails to halt the bloodshed. But rights activists brushed off the threats as ineffective, saying the death toll already has exceeded those seen during the recent uprisings in Yemen and Tunisia. “It is clear the international community is still giving the regime chances,” said Rami Abdul-Rahman, Director of the Syrian Observatory for Human Rights. More than 750 people have been killed and thousands detained since the uprising began in mid-March, touched off by the arrest of teenagers who scrawled anti-regime graffiti on a wall. In recent weeks, Assad has dispatched soldiers backed by army tanks and snipers across the country, saying security forces are rooting out “armed terrorist groups” and thugs. On Wednesday, the army shelled three neighborhoods in Homs, the country's third-largest city and home to one of Syria's two oil refineries. Shelling and heavy gunfire also were reported in the villages of Al-Haraa, Inkhil and Tafas outside Daraa, the southern city where the uprising began. UN chief Ban Ki-moon urged Assad, in power since 2000, to refrain from using excessive force. “I urge again President Assad to heed calls for reform and freedom and to desists from excessive force and mass arrest of peaceful demonstrators,” Ban told journalists in Geneva.